The can be found elsewhere and as follows:
<span>A. of magnetic effects.
B. the ball tries to pull the rod’s electrons over to it.
C. the rod polarizes the metal.
D. the rod and the ball have opposite charges.
</span><span>
I believe the correct answer is option C. If a negatively charged rod is held near a neutral metal ball, the ball is attracted to the rod. this happens because </span>the rod polarizes the metal. Hope this answers the question.
From Carnot's theorem, for any engine working between these two temperatures:
efficiency <= (1-tc/th) * 100
Given: tc = 300k (from question assuming it is not 5300 as it seems)
For a, th = 900k, efficiency = (1-300/900) = 70%
For b, th = 500k, efficiency = (1-300/500) = 40%
For c, th = 375k, efficiency = (1-300/375) = 20%
Hence in case of a and b, efficiency claimed is lesser than efficiency calculated, which is valid case and in case of c, however efficiency claimed is greater which is invalid.
The magnification <u>is 31.16.</u>
Magnification is the process of increasing the apparent size of something rather than its physical size. This increase is quantified by a calculated number, also called the "factor". If this number is less than 1, it means size reduction, sometimes called size reduction or reduction.
u = -19.3
f = -18.7 cm.
m = f/f-u
= -18.7/-18.7 +19.3
<u>= 31.16</u>
The term magnification refers to the size of the image produced by the lens compared to the size of the object. For lenses: Magnification "m" is the ratio of image height to object height. The magnification of a lens is defined as the ratio of image height to object height. It is also given by image distance and object distance. equal to the ratio of image distance to object distance.
Learn more about magnification here:-brainly.com/question/15744335
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